COMPETITIVE INTERACTIONS BETWEEN THE LAND SNAILS THEBA PISANA (MÜLLER) AND CERNUELLA VIRGATA (DA COSTA) FROM SOUTH AUSTRALIA

1988 ◽  
Vol 54 (3) ◽  
pp. 251-258 ◽  
Author(s):  
M.A. SMALLRIDGE ◽  
G.C. KIRBY
Keyword(s):  
South Australia ◽  
Land Snails ◽  
Competitive Interactions ◽  
Theba Pisana

Seasonal variation in rates of sporocyst and metacercarial infection by Brachylaima cribbi in helicid and hygromiid land snails on the Yorke Peninsula, South Australia

2005 ◽  
Vol 53 (6) ◽  
pp. 375 ◽  
Author(s):  
A. R. Butcher ◽  
D. I. Grove
Keyword(s):  
Seasonal Variation ◽  
Seasonal Variations ◽  
Infected Snail ◽  
South Australia ◽  
Land Snails ◽  
Infection Rates ◽  
Intermediate Hosts ◽  
Trematode Parasite ◽  
Yorke Peninsula ◽  
Theba Pisana

Brachylaima cribbi is a terrestrial trematode parasite of humans and other mammals, birds and reptiles, with helicid and hygromiid summer-aestivating land snails acting as first and second intermediate hosts. Beginning in April, seasonal variations in rates of sporocyst and metacercarial infection by B. cribbi were studied in Cochlicella acuta, Cernuella virgata and Theba pisana over 1 year at four ecologically diverse sites on the Yorke Peninsula, South Australia. The overall mean sporocyst prevalence rate in April was 2.7%. Sporocyst prevalences peaked during spring (10–78% for C. acuta, 12–44% for C. virgata and 10–18% for T. pisana). Metacercarial infection rates varied markedly from 10% to 98% at the start of the study. Overall metacercarial infection rates peaked with winter rains for T. pisana (average 50% infected) and in spring for C. acuta and C. virgata (average 80% infected) then declined in summer for all species. The average numbers of metacercariae per infected snail over the study period were 5.4 for C. virgata, 3.9 for C. acuta and 2.2 for T. pisana, with maximum numbers in winter or spring. Conditions on the Yorke Peninsula favour hyperinfection with this parasite.

Interactions between the land snails Theba pisana and Cernuella virgata in the laboratory

2020 ◽  
Author(s):  
Geoff H Baker
Keyword(s):  
Laboratory Experiments ◽  
Distribution Patterns ◽  
Land Snails ◽  
Snail Species ◽  
Agricultural Pests ◽  
Large Numbers ◽  
Small Scales ◽  
Novel Method ◽  
Theba Pisana ◽  
Inhibitory Components

ABSTRACT Two Mediterranean snails, Theba pisana and Cernuella virgata, are agricultural pests in southern Australia. The two species are rarely found together in large numbers in the field, at small scales (<1 m2). In laboratory experiments, the presence of T. pisana reduced the survival of C. virgata, but only when food (carrot + lettuce) was provided. When C. virgata was exposed to only the mucus trails and faeces of T. pisana, produced while feeding on lettuce, both the survival and activity of C. virgata were reduced. When carrot was substituted for lettuce, there was less effect. In addition, when C. virgata was exposed to T. pisana’s faeces only, derived from access to a mix of lettuce and carrot, there was no effect on C. virgata’s survival. The observed reductions in the survival of C. virgata were stronger in autumn (the breeding season for both snail species) compared with spring. Inhibitory components within the mucus trails of T. pisana may (1) help explain the observed distribution patterns of the two species at small scales in the field and (2) provide a novel method for control of pest populations of C. virgata, in some situations.

Physiological traits of land snails Theba pisana as simple endpoints to assess the exposure to some pollutants

2019 ◽  
Vol 26 (7) ◽  
pp. 6922-6930 ◽  
Author(s):  
Kawther S. El-Gendy ◽  
Mohamed A. Radwan ◽  
Amira F. Gad ◽  
Awatef E. Khamis ◽  
El-Sayed H. Eshra
Keyword(s):  
Land Snails ◽  
Physiological Traits ◽  
Theba Pisana

Soil surface temperature and mortality in land snails: implications for successful management

2003 ◽  
Vol 43 (11) ◽  
pp. 1351 ◽  
Author(s):  
V. Kempster ◽  
S. Charwat
Keyword(s):  
Laboratory Experiments ◽  
Control Strategies ◽  
High Surface ◽  
Soil Surface ◽  
Land Snails ◽  
Successful Management ◽  
Economic Problems ◽  
Surface Temperatures ◽  
Theba Pisana ◽  
Soil Surface Temperature

Three species of land snails, Theba pisana (Müller, 1774), Cernuella virgata (Da Costa, 1778) and Cochlicella acuta (Müller, 1774), introduced to Australia from the Mediterranean region, cause significant economic problems in harvested crops in southern Australia. One of the strategies for post-harvest control of these snails involves stubble management to knock the snails onto the hot ground during summer. Farmers report variable results with this strategy, which could be due to varying heat tolerances between the 3 species. In a series of laboratory experiments, field-collected snails of the 3 species were tested for their ability to survive high surface temperatures for varying periods of time. The results reported here indicate differences between the 3 species in their tolerance of soil surface temperatures, and suggest that the variable results noted in the field are due at least in part to the differing heat tolerances of the 3 species. When adult snails were placed in incubators at a constant temperature, all T. pisana died after 3 h at 55°C, while C. virgata and C. acuta survived longer, with 100% mortality only after 2 successive 6-h exposures at 55°C. Weight loss of snails was measured after heat treatment to estimate water loss under these conditions. Recommendations are made for more effective mechanical control strategies for snails in the field during summer.

scholarly journals Toxicity of Euphorbia helioscopia pellets to two Phytophagous molluscs, Theba pisana Müller, 1774 (Pulmonata: Helicidae) and Arion hortensis férussac, 1819 (Pulmonata: Arionidae)

2018 ◽  
Vol 33 (3-4) ◽  
pp. 241-252
Author(s):  
Anjoud Harmouzi ◽  
Ahmed Boughdad ◽  
Ammari El ◽  
Abdelaziz Chaouch
Keyword(s):  
Control Method ◽  
Plant Protection ◽  
Environmentally Friendly ◽  
Land Snails ◽  
Synthetic Product ◽  
Plant Organ ◽  
The World ◽  
Mollusc Species ◽  
Theba Pisana ◽  
Euphorbia Helioscopia

Harmful land snails and slugs are currently one of the most important threats facing agriculture in many parts of the world. Synthetic molluscicides are the main control method against these gastropods. However, dangers caused by these chemicals to the environment have led scientists to research for environmentally friendly alternatives. The objective of our work was to test and evaluate food pellets containing roots, stems, leaves or flowers of Euphorbia helioscopia against Theba pisana and Arion hortensis adults. Toxicity of the prepared pellets varied depending on plant organ and mollusc species tested. Pellets made of stems (LD50 = 1.35 g / 100 ml of agar at 2%) and leaves (LD50 = 1.39 g / 100 ml of 2% agar) proved more toxic to adult snails than those made of roots and flowers, which had no significant effects. In the case of slugs, pellets made of leaves (LD50 = 1.14 g / 100 ml of 2% agar) were more toxic than those made of stems (LD50 = 1.33 g / 100 ml of 2% agar), flowers (LD50 = 1.75 g / 100 ml of 2% agar) and roots (LD50 = 1.98 g / 100 ml of 2% agar). Compared to a synthetic product containing metaldehyde 5%, the results show that the use of these molluscicides derived from plants as pellets is environment- and healthconscious, targeted and economical. These products can be used in plant protection against phytophagous slugs and snails.

Hunger and satiety determine foraging decissions in land snails: Evidence from the invasive species Theba pisana

2019 ◽  
Vol 164 ◽  
pp. 230-236
Author(s):  
Marcial Rodríguez ◽  
Beatriz Álvarez ◽  
Ignacio Loy
Keyword(s):  
Invasive Species ◽  
Land Snails ◽  
Theba Pisana

The population dynamics of the mediterranean snails Cernuella virgata, Cochlicella acuta (Hygromiidae) and Theba pisana (Helicidae) in pasture - cereal rotations in South Australia: a 20-year study

2008 ◽  
Vol 48 (12) ◽  
pp. 1514 ◽  
Author(s):  
G. H. Baker
Keyword(s):  
Population Dynamics ◽  
Near Field ◽  
South Australia ◽  
Habitat Choice ◽  
Snail Species ◽  
Large Numbers ◽  
Yorke Peninsula ◽  
Sampling Scale ◽  
Theba Pisana ◽  
Peak Abundance

The snails Cernuella virgata, Cochlicella acuta and Theba pisana are introduced pests of grain crops and pastures in southern Australia. The population dynamics of these three species of snail were studied for 20 years in two adjacent fields where they coexisted on a farm on the Yorke Peninsula in South Australia. The fields were used for pasture–cereal rotations. Surveys were conducted in autumn and spring each year, coinciding respectively with the start of the breeding season and peak abundance of snails (mostly juveniles). Populations varied greatly in abundance between years and between species, but snails were generally most common in spring, in wet years, especially those with wet autumns and wet springs. Rainfall early in a particular year (i.e. at sowing of crops in autumn) can thus be used to predict the likelihood of heavy snail infestations later in spring (i.e. at harvest). In contrast, the abundance of adult snails in autumn was a poor predictor of the subsequent abundance of juvenile snails in spring, especially in crops. There were no significant correlations, at field scale, between the average abundance of the three species of snail in spring, in either pastures or crops. However, at a sampling scale of 0.25 m2, there were consistent, negative relationships between the abundance of all three snail species. Such patterns may reflect either competitive interactions between snails or subtle differences in micro-habitat choice. Patterns in the abundance of snails (e.g. large numbers near field edges) were suggestive of occasional invasion from dense populations in adjacent fields.

scholarly journals The alien invasive land snail Theba pisana in the West Coast National Park: Is there cause for concern?

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Lizelle J. Odendaal ◽  
Tanya M. Haupt ◽  
Charles L. Griffiths
Keyword(s):  
West Coast ◽  
National Park ◽  
Feeding Habits ◽  
Activity Patterns ◽  
Average Density ◽  
Land Snails ◽  
Adult Size ◽  
The West ◽  
Theba Pisana ◽  
Very High

The distribution, abundance, size distribution and diurnal activity patterns of invasive land snails, Theba pisana, in the West Coast National Park (WCNP), South Africa, were investigated. The park was divided into 1 km2 grids, within each of which five 1 m2 quadrat counts of live snails were recorded. Of 106 grids sampled, 19% contained live snails. The average density of snails was 4.04 m-2 ± 24.9, significantly lower than in disturbed habitats adjacent to the park (57 m-2 ± 96.25), but very high densities were recorded at two sites. Snails were most abundant along roadsides and densities decreased dramatically with distance from roads. T. pisana in the WCNP appear to have an annual lifecycle, breeding in autumn to winter and growing to adult size of about 14 mm diameter by the end of the following summer. Snails were observed on a wide variety of endemic and introduced plant species and appeared to have a catholic diet. They are active mostly at night and especially during periods of high humidity, irrespective of temperature. Given the very high densities that T. pisana can attain at some sites, plus their apparently catholic feeding habits, their potential impact on the vegetation of the park is cause for concern and should be further investigated. Control of the main colonies should also be considered.

Children, snails and worms: the Brachylaima cribbi story

2016 ◽  
Vol 37 (1) ◽  
pp. 30 ◽  
Author(s):  
Andrew R Butcher
Keyword(s):  
Life Cycle ◽  
South America ◽  
South Australia ◽  
Land Snails ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Wide Range ◽  
Terrestrial Life ◽  
North And South America ◽  
North And South

Brachylaimids are parasitic trematode fluke worms that have a terrestrial life cycle involving land snails and slugs as the first and/or second intermediate hosts for the cercarial and metacercarial larval stages. A wide range of mammals, birds, reptiles and amphibians are the definitive hosts for the adult worm. Brachylaima spp. have been reported from most continents including Europe, Africa, Asia, North and South America and Australia. There are over 70 described species in the genus with seven species indigenous to Australia. Although Brachylaima spp. are a cosmopolitan terrestrial trematode they have not been recorded to infect humans other than the three Brachylaima cribbi infections reported in two children and an adult from South Australia.

Sign in / Sign up

Export Citation Format

Share Document